Begin by bringing a large pot of salted water to a rolling boil over high heat. Once boiling, add the rigatoni and cook for 8-10 minutes, stirring occasionally. Reserve 1 cup of starchy pasta water, drain the rigatoni, and set aside.

In a spacious skillet, heat 2 tablespoons of olive oil over medium heat. Add the diced onion, cooking for 4-5 minutes until translucent and fragrant.

Stir in 3 cloves of minced garlic, cooking for an additional minute until aromatic. Avoid browning the garlic.

Add 1 pound of crumbled Italian sausage to the skillet. Cook for 6-8 minutes until browned, stirring frequently.

Pour in a can of fire-roasted tomatoes, mixing well. Let it simmer for 15 minutes on medium-low heat until the sauce thickens.

Taste the sauce and season with a pinch of red chili flakes, salt, and pepper. Simmer for a couple more minutes.

Lower the heat and gradually pour in 1 cup of heavy cream, stirring to combine. Let simmer for another 5-7 minutes until thickened.

Sprinkle in ½ cup of grated Parmesan cheese, stirring until melted. Adjust sauce consistency with reserved pasta water if needed.

Toss the cooked rigatoni into the skillet, stirring to coat fully with the creamy sauce.

Plate and garnish with extra Parmesan cheese and fresh basil leaves. Serve hot.